Everything you wanted to know about taps but were afraid to ask, styles of taps, class of thread , gh numbers , basic point in thread measurement , constants for finding pitch
How to Use a Tap and Die Set | Tameson.com
GearWrench 3887 Ratcheting Tap Die Set Sae Metric Auto Locking 75 Pc Silver New | eBay
Tap & Die Sets - Harbor Freight Tools
Performance Tool W4001DB 40 Piece SAE Tap & Die Set | eBay
910766-5 Tap and Die Set: 41 Pieces, 1/2"-20 Min. Tap Thread Size, 1/2"-20 Max. Die Thread Size | Imperial Supplies